title: Sorption of antibiotic sulfamethoxazole varies with biochars produced at different temperatures.
abstract: Sorption of sulfonamides on biochars is poorly understood, thus sulfamethoxazole (SMX) sorption on biochars produced at 300-600 °C was determined as a function of pH and SMX concentration, as well as the inorganic fractions in the biochars. Neutral SMX molecules (SMX(0)) were dominant for sorption at pH 1.0-6.0. Above pH 7.0, although biochars surfaces were negatively-charged, anionic SMX species sorption increased with pH and is regulated via charge-assisted H-bonds. SMX(0) sorption at pH 5.0 was nonlinear and adsorption-dominant for all the biochars via hydrophobic interaction, π-π electron donor-acceptor interaction and pore-filling. The removal of inorganic fraction reduced SMX sorption by low-temperature biochars (e.g., 300 °C), but enhanced the sorption by high-temperature biochars (e.g., 600 °C) due to the temperature-dependent inorganic fractions in the biochars. These observations are useful for producing designer biochars as engineered sorbents to reduce the bioavailability of antibiotics and/or predict the fate of sulfonamides in biochar-amended soils.
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zheng
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Zhao
authors.forename: Stephen
authors.initials: S
authors.lastname: Herbert
authors.forename: Baoshan
authors.initials: B
authors.lastname: Xing
mesh_terms: D000327:Adsorption; D000900:Anti-Bacterial Agents / Q000032:analysis / Q000737:chemistry*; D002606:Charcoal / Q000737:chemistry*; D052918:Environmental Restoration and Remediation; D008956:Models, Chemical; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D013420:Sulfamethoxazole / Q000032:analysis / Q000737:chemistry*; D013696:Temperature
chemical_list: D000900:Anti-Bacterial Agents; D012987:Soil; D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal; D013420:Sulfamethoxazole
keywords: Antibiotics; Biochar; Inorganic fractions; Sorption; Sulfamethoxazole